Patent GB-191209459-A (GB)
Title: Buttonhole Cutting Mechanism for Sewing Machines.
Inventor: FAIRWEATHER WALLACE
IPC: D05B37/02
Filed: 1912-04-22
Granted: 1912-10-31
Abstract: 9459. Fairweather, W., [Singer Manufacturing Co.]. April 22. Button-hole sewing-machines. - The machine comprises a laterally jogging needle 21, and complemental stitch-forming mechanism 30, 31, 32, both parts being rotatable by racks 58, 60 actuated by the feed cam 47 in order to carry the stitching round the button - hole. The stitching-mechanism shafts 6, 12 are driven by a pulley 11 through a controlling-clutch 156, and the cutting - mechanism operating - shaft 91 is separately driven by a pulley 127 through a special clutch device. The upper cutting-member 74 carying the adjustable knife 78, and the lower member 75 carrying the anvil 77 are pivoted on a fulcrum 72, Figs. 1 and 3, which is mounted on a block 69 adapted to slide in guides in the bed 2 so as to advance the cutters into and withdraw them from the cutting position. The block is reciprocated by a rod 111 having a. cam-roller 115 running in a cam-track in a disk 117 on the shaft 91. The lower member 75 is kept up to its work by a circular cam 92, and the upper member is actuated by a suitably-shaped cam 93. The members are connected by a spring 90, and the cutter 74 has an adjustable wearing-plate 96 engaging the cam 93. The needle-throat 42, Figs. 1 and 7, is carried by a frame 36 pivoted to the rotary housing 25. During the stitching operation, the frame 36 is locked in position by the engagement of an extension 44 with a bar 120 mounted on the reciprocatory block 69. When the block is advanced prior to cutting, the extension 44 drops into a cam notch 122, the needle throat being pushed out of the way by the anvil 77. When, on the part 25 being rotated during the stitching operation, the parts 44 and 120 pass out of contact, the part 44 is locked by a rim 126 screwed to the frame 124. The clutches controlling the shafts 6, 91 are interconnected and the cutting and stitching operations take place automatically. A starting-finger 199, Figs. 1 and 17, is provided. It is connected by a rod 198 with a lever 203 by which the clutch on the shaft 91 is put in. This shaft makes one revolution and towards the end, puts in the clutch 156 of the shaft 6. The bar 198 is locked in position, except at starting, by a spring-pressed detent 205 which is engaged by the rack-bar 60. The clutch for the shaft 91 comprises a rim 128, Figs. 3 and 13, on the pulley 127, notched at 129 for engagement with a spring-pressed slide 130 mounted in a disk 132 on the shaft 91. Normally the slide 130 is held retracted by a cam 134 engaging a pin 133 on it, but it is released to clutch the parts by rocking the lever 135 upon which the cam 134 is mounted. The lever 135 is pivoted at 136 and is moved to free the slide 130 by the lever 203 connected with the starting finger 199, and to withdraw the slide after one revolution of the shaft 91 by a cam 138. The clutch 156 is put in by a cam 172 on the shaft 91 acting through the roller 171, and levers 169, 162, Figs. 1 and 11, and is taken out by a spring 168 when a catch holding the arm 169 is liberated by a lever 186, Fig. 3, actuated by an adjustable projection 191 on the feed wheel 47. The clutch on the shaft 6 is constructed and operated in the following manner. The driven pulley 11, Figs. 11 and 12, is recessed to take a disk 153 which is mounted on the shaft 6 and has a clutch plate 154 on its periphery. The plate 154 is pressed into contact with the pulley by a cam pin 155 fixed to and forming the pivot of a plate 156, which is pressed to keep the clutch in by a spring 158 acting on a pin 157. When the arm 169 is tripped by the lever 186, the spring- pressed block 161 rides up the cam edge 166, thus slowing the shaft 6, and finally enters the notch 159 and swings the plate 156 slightly so as to relieve the pressure on the clutch surface 154. This takes the clutch out.